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United States Patent | 5,644,428 |
Heinrich | July 1, 1997 |
An optical beam splitter separates an input beam into two exit beams which angularly diverge from each other by a continuously variable amount. The degree of angular divergence is controlled by rotating a compound cylinder composed of a half-cylinder of birefringent material and a half-cylinder of glass about their common cylindrical axis. The cylinder is placed between a pair of plano-concave sections, which match the curvature and materials of the cylinder. The ordinary refractive index of the birefringent half-cylinder section is matched to that of the isotropic glass half-cylinder, which limits the changes in exit beam angular divergence to only one of the beams. A phase compensation block preceding the birefringent plano-concave section and the compound cylinder prevents the accumulation of optical phase between the two exit beams. The interfaces between the fixed birefringent plano-concave section and the birefringent half-cylinder as well as the glass half-cylinder and the fixed glass plano-concave sections are immersed in an index matching oil to minimize optical wavefront distortion at these interfaces.
Inventors: | Heinrich; Harley Kent (Brewster, NY) |
Assignee: | International Business Machines Corporation (Armonk, NY) |
Appl. No.: | 025501 |
Filed: | March 3, 1993 |
Current U.S. Class: | 359/494; 359/301; 359/304; 359/495; 359/497 |
Intern'l Class: | G02B 005/30; G02B 026/08; G02B 027/28 |
Field of Search: | 359/494,495,496,497,499,500,301,304,583,483 |
2552383 | May., 1951 | Rylsky et al. | 359/494. |
3183763 | May., 1965 | Koester | 359/497. |
3391972 | Jul., 1968 | Harris et al. | |
3410624 | Nov., 1968 | Schmidt. | |
3432238 | Mar., 1969 | Girard | 359/494. |
3482899 | Dec., 1969 | Schmidt. | |
3511556 | May., 1970 | Ammann. | |
3520592 | Jul., 1970 | Leib et al. | 359/500. |
3536375 | Oct., 1970 | Mansell. | |
3572895 | Mar., 1971 | Schmidt et al. | |
3622225 | Nov., 1971 | Buchman et al. | 359/583. |
3704997 | Dec., 1972 | Smith. | |
3741625 | Jun., 1973 | Saleh | 359/583. |
3758201 | Sep., 1973 | MacNeille | 359/497. |
4129357 | Dec., 1978 | Title. | |
4563058 | Jan., 1986 | Yardy | 359/583. |
4588263 | May., 1986 | Cohen et al. | 359/495. |
4643534 | Feb., 1987 | Chun et al. | 359/497. |
4747673 | May., 1988 | Marrs et al. | 359/583. |
4758092 | Jul., 1988 | Heinrich et al. | |
4766303 | Aug., 1988 | Yoshizumi et al. | 359/500. |
5212594 | May., 1993 | Joynes | 359/495. |
5223956 | Jun., 1993 | Kramer et al. | 359/495. |
B. R. Hemenway et al., "Optical Detection of Charge Modulation in Silicon Intergrated . . . " IEEE Electron Device Letters, vol. EDL-8, No. 8, Aug. 1987 pp. 344-346. H.K. Heinrich et al. "Noninvasive Sheet Charge Density Probe For Integrated Silicon Devices" Appl. Phys. Lett. 48 (16), 21 Apr. 1986, pp. 1066-1068. J. I. Thackara et al., "Electro-Optic Sampling of Poled Organic Media", Appl. Phys. Lett. 59 (10), 2 Sep. 1991, pp. 1159-1161. H.K. Heinrich et al. "Measurement of Real-Time Digital Signals in a Silicon Bipolar Junction Transistor Using . . . ", Electron. Lett. 22, pp. 650-652, 1986. R. Drougard et al. "New Polarization Interferometer for Fourier Analysis", J. Opt. Soc. Am. 55, pp. 1638-1642, 1965. M. Francon et al. "Polarization Interferometers Applications in Microscopy and Macroscopy", Wiley-Interscience, J. Wiley & Sons, Ltd., pp. 24-25 and 40-43. |